Variable condenser



Nov; 24,1925. 1,562,629

H. GERN$BACK VARIABLE CQNDENSER Filed Sept. 27, 1925 12', 13, for attaching purposes,

Patented Nov. 24, 1925.

UNI TED STATES iruoo eamrsnnox, or NEW Yonk, n. Y.

VAR ABLE OQNDENSER,

Application filed September 27, 1823. Serial No. 665,082.

Other objects and the novel-' flii ttiiesof construction, combination and relation of parts which make possible the attainment of all such objects will appear 'as' the speciiication proceeds. I I

In the drawing accompanying and forming part of this specification there-1s illustrated but one of the many possible practical embodiments of the invention, it be'- ing understood that the form may vary without departure from the broadspirit and scope ofthe invention as hereinafter defined and claimed.

Figure l is a plan view of a form of the condenser as constructed for either table or, panel mounting.

Figure 2 is an edge and broken sectional view or the same.

Figure 3 is a broken sectional view as taken on substantially the plane of line 33 of Figure 2. 4 I

The base of the condenser illustrated is made up of two rigid plates or sheets 5, 6, of suitable insulating material of substantially rectangular outline and secured. together in spaced overstanding relation by interposed corner posts 7, 8, 9, 10, with which fastening screws 11 are engaged. These base plates are shown as duplicates, each constructed with projectio end lugs disposed at opposite sidcz: of a longitudinal center line, the plates being reversed in the assembling to eiiect a vertical offsetting of these lugs, so as to render them directly accessible either at the front or at the back of the condenser. Tapped holes 14 may be provided in the lugs to-take attaching or supporting screws. In the case of mounting the condenser on a table or other support, the attaching screws may be engaged with or passed through the end lugs on the back plate 5, whereas, for a panel mounting, the

screws passed through the panel may be engaged with the lugs on the front plate and in both events the lugs on one base plate tare'out of the way and do not interfere with the proper use of the other set of lugs.

The condenser elements consist of the two plates 15, 16, the first being shown as a thin metallic sheet, secured at one 'end of the base beneath the osts '9, 10, and the second or upper plate ing shown as a heavier sheet secured beneaththe opposite set of posts 7, 8' and bowed upwardly away from the firstble sheet of, copper and the upper plate should be of a good resilient material, such as spring brass. The bend in the brass sheet may be 1n the form of a flat arch as shown, starting on a line at 17, adjacent the securing posts andappnoximately over the end of the copper sheet at 18. I

A layer of'solid" dielectric is indicated at 19, interposed between the two cooperating plates. In practice this layer should be thin to allow the plates to come closely together. A film of insulating enamel applied to the face of the lower or relatively stationary plateanswers this purpose and is flexible so as to yield with any slight movements of this lower flexible plate.

Means for flexing the upper plate toward the lower is shownvin the form of a nut 20 i held loosely on top of the arched plate be tween integrallugs 21 struck up from such plate and engaged'by the screw-threads 22 of a stem 23, journaled in a bearing 24 in the uppbr base plate and provided with an operating knob 25 and scale 26.

In Figure 2 the. adjustable spring plate is indicated in full lines as fully separated plate. The lower. plate may be a thin flexifrom the} companion lower plate, the

capacity being then reduced substantially to zero and the broken lines show how-,as pressure is applied by the turning of the screw in the nut, the arch, in the plate will be gradually flattened out until the plates are brought together into flat face to face relation separated only by the thin layer of dielectric.

To avoid friction and wearing away of the dielectric, the spring plate is shown as havmg an extension or ton e 27, of less width than the body of the p ate so as to project between the posts 9, 10, beyond the end of the lower plate into sliding engagement with menses during the flattening of the plate and whereby wear on the dielectric is avoided 4. A variable condenser comprising ensulating base plates, posts securing the same in.

spaced relation, a condenser plate engaged by and electrically connected with one of such posts, a cooperating resilient condenser plate held by and electrically connected with one of the other os'ts, terminal means for the lates, carried b said osts, a dielectric ayer between t e con enser plates ,and means for flexing the resilient plate.

5. A variable condenser comprising insu' lating base plates, posts'securing the same in spacedrelation, a condenser plate held by, and electrically connected with one of such posts, a coo crating resilient condenser plate held by an electrically connected with one of the other posts, terminal means for the plates carried by said posts, a dielectric layer between the condenser plates, means for flexing the resilient plate and a layer of cushioning material also held by the postsat the back of the first condenser plate to enable the same to adapt itself to the varying pressure of the resilient plate. f

6. A variable condenser comprising insulating base plates secured in spaced relation and provided with end lugs arranged those of one plate ofiset with respect to those of the other late, cooperating condenser plates motnmted 1n the space between theinsulat ing plates with a dielectric layer therebe-' sulating plates for eifectinp a tween and means mounted on one of the ina relative. adjustment of the condenser p tes.

7. A variable condenser comprising insulating base plates, metallic posts securing the same in spaced relation, an insulating cover extending'about said Posts and pro viding with the base plates an enclosed in- ,sulating chamber, cooperating condenser plates mounted within said chamber with a insulatingbase, a layer of cushioning cloth material on said base, a thin fiexible,"c0n-' denser plate on said cushioning layer, a thin flexible dielectric layer on said plate, a second flexible-condenser plate mounted on the base over the dielectric layer and adjustable means for efi'ectingsuch adjustment of the su'ond plate to thereby force the plates and interposed dielectric intointimate se1f-adjusting contact.

In witness whereof, I have hereunto set my hand this 24th day of September, 1923.

HUGO GERNSB AGK.

toward and away from the first plate and 

